Wastewater purification with nanoparticle-treated bed

Patent metadata

Field	Value
Publication number	US-9540251-B2
Application number	US-201414332815-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Apr 29, 2008
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

Nanoparticle-treated particle packs, such as sand beds, may effectively filter and purify liquids such as waste water. When tiny contaminant particles in waste water flow through the particle pack, the nanoparticles will capture and hold the tiny contaminant particles within the pack due to the nanoparticles' surface forces, including, but not necessarily limited to van der Waals and electrostatic forces. Coating agents such as alcohols, glycols, polyols, vegetable oil, and mineral oils may help apply the nanoparticles to the particle surfaces in the filter beds or packs.

First claim

What is claimed is:

1. A method for purifying an aqueous liquid containing clay particles, the method comprising:
contacting said aqueous liquid with a particle pack comprising substrate particles and comparatively smaller particulate additives;
where the substrate particles are comparatively larger than the particulate additives and are selected from the group consisting of sand, gravel, ceramic beads, glass beads, and combinations thereof,
where the particle pack is at least partially coated with a coating agent comprising a mineral oil,
where the particulate additives have a mean particle size of 1000 nm or less and are alkaline earth metal hydroxides; and

attracting said clay particles from the aqueous liquid to the particulate additives to purify the aqueous liquid.

2. The method of claim 1 where
the alkaline earth metal is selected from the group consisting of magnesium, calcium, and mixtures thereof.

3. The method of claim 1 where the particulate additives are present in an amount ranging from about 1 part by weight particulate additive for about 200 to about 5000 parts by weight of the particle pack.

4. The method of claim 1 where the mean particle size of the particulate additives is from about 4 nm to about 500 nm.

5. The method of claim 1 where the substrate particles in the particle pack have a mean particle size ranging from about 2000 microns to about 45 microns.

6. A method for purifying aqueous fluids containing clay particles, the method comprising:
contacting said aqueous liquid with a particle pack comprising substrate particles and comparatively smaller particulate additives;
where the substrate particles are comparatively larger than the particulate additives, have a mean particle size of from about 2000 microns to about 45 microns and are selected from the group consisting of sand, gravel, ceramic beads, glass beads, and combinations thereof, and where the particulate additives:
where the particle pack is at least partially coated with a coating agent comprising a mineral oil,
where the particulate additives have a mean particle size of 1000 nm or less and are alkaline earth metal hydroxides;
where the particulate additives range from about 1 part by weight for about 200 to about 5000 parts by weight of the particle pack; and

attracting said clay particles from the aqueous liquid to the particulate additives to purify the aqueous liquid.

7. The method of claim 6 where
the alkaline earth metal is selected from the group consisting of magnesium, calcium, and mixtures thereof.

8. The method of claim 6 where the mean particle size of the particulate additives is from about 4 nm to about 500 nm.

9. A method for purifying an aqueous liquid containing clay particles, the method comprising:
contacting said aqueous liquid with a particle pack comprising substrate particles and comparatively smaller particulate additives;
where the substrate particles are comparatively larger than the particulate additives and are selected from the group consisting of sand, gravel, ceramic beads, glass beads, and combinations thereof where the particle pack is at least partially coated with a coating agent comprising a mineral oil,
where the particulate additives are of smaller mean particle size than the substrate particles, where the particulate additives are at least partially coated on the substrate particles by the mineral oil, and where the particulate additives have a mean particle size of 1000 nm or less and are alkaline earth metal hydroxides; and

attracting said clay particles from the aqueous liquid to the particulate additives to purify the aqueous liquid.

10. The method of claim 9 where
the alkaline earth metal is selected from the group consisting of magnesium, calcium, and mixtures thereof.

11. The method of claim 9 where the particulate additives are present in an amount ranging from about 1 part by weight particulate additive for about 200 to about 5000 parts by weight of the particle pack.

12. The method of claim 9 where the mean particle size of the particulate additives is from about 4 nm to about 500 nm.

13. The method of claim 9 where the substrate particles in the particle pack have a mean particle size ranging from about 2000 microns to about 45 microns.

Assignees

• Baker Hughes Inc

Inventors

• Huang Tianping
• Crews James B

Classifications

• C02F1/001

  Processes for the treatment of water whereby the filtration technique is of importance (C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00) · CPC title

• B01J20/08

  comprising aluminium oxide or hydroxide; comprising bauxite · CPC title

• Y10T428/252

  Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.] · CPC title

• C02F1/281

  using inorganic sorbents · CPC title

• B01J20/041

  Oxides or hydroxides · CPC title